Indi an Journal of Chemistry Vol. 41A, March 2002, pp. 560-562 Synthesis and characterization of ruthenium(II) complexes of different types of potential unsymmetrical hemilabile P-O and P-S donors ligands Pankaj Das. Manab Sha rm a, Nandini Kum ari, Dilip Konwar & Dipak Kumar DUll a* Material Science Di vision, Regional Research Laboratory (CS IR ) Jorhat, 785 006 Assa m. Indi a Received 6 A I/ gus' 200 1; revised 19 Novell/ bel' 2001 Various po te nti al bid e nt ate he mil ab il e ligands with different aliphati c bac kbones, such as Ph 2PCH 2C H2COOC2H5(a ), Ph 2 PCl-I (C H, )COOCH 3 (b), Ph 2 PCH 2 0CH,(c), Ph 2 PC H 2 CH r OC2H5( d). Ph 2PCH2CH1SC2H5(e) react with [R uCI 2 (PPh J )J] in 3: I mola r rati o to produ ce co mpl exes of th e type [ RUC! 2(P-Xh( Pn X)] ( la-e ) Iwhere P-X = 11 1- (P) coordinated; Pn X = 11 2- (P, X) coordinated li ga nd; X = 0 , S]. On th e o th er hand , reac ti on of a liga nd containing an aro ma tic ba c kbone unit such as with IRuCI 2 (PPh 3 )3 ] produ ces a bis-chelat e compl ex [RuCI 2 (Pn Oh ] (2). The co mpl exes have been charac te ri zed by e le mental an alysis, IR , I H. and 31 p{ I H l NM R spec tr oscopy. Potential bidentate li ga nds partic ul arly tertiary ph os- phines functionalized with a hetero donor atom like oxygen l . IS , sulphur l6 . 19 etc. generally ca ll ed hemilabi le li gand have gained much imp or tance. Due to th e pres- ence of two different types of donors i.e. 'Soft phos- phorus and Hard oxyge n' or ' Soft pho sphorus and Soft sulphur' th ey are capable of coo rdinating to the metal either as a monodentate or bidentate fashion depending on the metal atom and its environment. In the last few years, there has been growing interest in the ruthenium(II) chemistry of such ligand s9- ls. 19 be- cause of their structural novelty, reactivity and cata- lytic activity. In this note, we report the synt hesis and spectro- scopic characterization of ruthenium(ll) comp lexes with different types of hem il abile li ga nds like Ph2PCH 2CH 2COOC2Hs, Ph 2 PCH(CH 3 )COOCH 3 , Ph 2 PCH 2 0CH 3 , Ph2PCH2CH 20C2Hs, Ph 2 PCH 1 CH 2 S- C 2 Hs and o-Ph2PC6H4COOC2H s. Experimental Th e starting complexes, [RuCh(PPh 3 hJ were pre- pared accor ding to the literature method 20. The lig- Email: dipakk.rdutta @yahoo.com ands Ph2PCH 2C H2C OO C2Hs, Ph 2 PCH (CH J )- C OOCH ), Ph 2 PCH 1 0CH j, Phl PC H1CH20C2Hs, Ph2PCH2CH 20 C2Hs and o -Ph 2PC6H4COOC2Hs were prepared by foilowing Isslaib 's general methods of preparation 11 . Other chemical reage nt s were of ana- lytical grade and used as received. All the reactions were carried out in dry solvents under nitrogen at- mosphe re. Elementa l analyses wer e per fo rme d using Perkin- Elmer 2400 elemental analyzer. IR spectra were re- co rded in KBr disc on a Perkin-Elmer system 2000 FT-IR spectro photome te r. The IH (300. 13 MH z) and Jlp{ IH} (121.49 MHz) NMR spectra were record ed at - 20 D C in CDCb so lution on a Bruker DPX- 300 spec- trophotomete r. Th e chemical shifts have been re- ported relative to SiMe4 as an internal reference for the former and 85% H J P0 4 as external referen ce for the latter. Synthesis of th e cOlllplexes To a solution of [RuCIz(PPh 3 hJ (0.05 mmo l) in CH 2 Cl 2 (10 ml), 0.160 mmol of the respective li ga nd was added and the solution was then refluxed und er nitrogen for 2-4 h during which the co lour of th e so - lution changed from dark brown to reddish brow n ( la-e, 2), yellow brown ( ld) and orange yellow (Ie) . The solvent was removed under reduced pressure to ge t a solid compo und. Th e product was washed thor- oughly with hexane pet-ether mixture to obtain the pure compound. Analytical data of the complexes (in %): la: Yield: 79; Found C, 59.67; H, 5.56 ; Calcd . for C S1 H s7 CIz0 6 P 3 Ru: C, 59.47; H, 5.53 lb: Yield: 83; Found C, 58.21 ; H, 5.11 ; Calcd. for C4s Hs ICh0 6PJRu : C, 58.35; H, 5.16 Ie : Yield: 8 1; Found C, 58 .67; H, 5.26; Calcd. for C41 H4S CbOJPJRu : C, 58.53 ; H, 5.22 ld : Yield: 77 ; Found C, 6i. I I; H, 5.97; Calcd . for C4 8Hs7 CI 20 JPJRu: C, 60.95; H, 6.03 Ie: Yield: 85; Fo und C, 57.87; H, 5.69, Calcd. for CSIHS7Cb0 6PJRu: C, 58.00 ; H, 5.74 2 : Yield: 67 ; Found C, 60.07; H, 4.52; Calcd. for C42H Js Ci20 4P2Ru: C, 60.14; H, 4.57. (Yields shown above are in resp ect of expected stoi- chiometric product i.e. 100% yield, but during wash- ing and purification certain amount of compound s are lost)